The invention relates to a furniture system with electrification, the furniture system having a plurality of structural elements formed for receiving functional furniture units. Furthermore, the invention relates to a multiple plug which makes the electrification of the furniture system possible.
Nowadays virtually every workplacexe2x80x94whether in the office, laboratory or homexe2x80x94is provided with a computer. Even telephones are often no longer operated by the current from the telephone line alone, but like every other item of electrical equipment have to be connected to the power supply system. Finally, to satisfy individual requirements for light (that is in offices with a plurality of workplaces), additional desk lamps or floor lamps are often used.
Conventionally, an extension cable with a multipoint connector is laid on the floor and has the various loads connected directly to it. Experience shows that this results in a tangle of cables, which cannot be satisfactory from aspects of safety or esthetics. To avoid such a tangle of cables, cable ducts are also known. These are laid in or on the floor, the wall or the ceiling.
Specifically in the case of modular furniture systems, there have been a wide variety of approaches to a solution. On the one hand, DE-A 196 21 547 A1 (USM) discloses a modular interior furnishing system comprising a plurality of different functional units, such as carcasses, work-surfaces, partition panels, light fittings, etc., each structural element of the interior furnishing system taking the form of a free-standing, vertical, closed rectangular frame. In order that cables can be accommodated in the frame, ducts or grooves are provided in the latter. On the other hand, bus bars have been used for the electrification of modular furniture systems. Such an approach is disclosed, for example, in WO 98/38705.
A further possibility for electrification of an interior space-dividing system with a switching system is shown in U.S. Pat. No. 5,595,495 A (Johnson et al.). The switching system controls panel-mounted receptacle units. Each panel is provided with a pre-cabled electrical system and has on the lower side a cable duct in which the electrification is accommodated. The panels set up alongside one another are electrically interconnected by means of multiple plugs with a flexible electrical connector. A housing can engage in slots in the frame of the panels and be displaced vertically at set increments.
GB 2 101 175 A (Project Office Furniture Ltd) shows an electrification system for panel screens with cable ducts, in which the electrical supply is accommodated. The continuous cable ducts can be displaced vertically at set increments along the longitudinal struts of the panel screens. Lines are arranged in the cable ducts, and terminals and sockets are arranged at the ends. By means of terminals, the cable ducts are connected to one another with a short cable or a spiral cable. The cable ducts may also be of an open design, in order that, for example, a socket unit can be laterally displaced in the cable duct.
The majority of the known electrification systems are intended for installation in buildings. To be mentioned by way of example are bus bars for lighting and those for setting sockets at freely selectable locations. These arrangements conform to the common safety standards, but are quite large and complicated in their construction. In addition, bus bar systems for special applications are known, but they usually fail to satisfy safety requirements.
Cases of electrification of entire furniture systems are known from display cabinet construction. In these cases, the levels formed by the individual parts of the structural element are covered with glass plates or metal sheets. The electrification takes place, for example, by cables permanently installed in the longitudinal struts and defined taps for light fittings. The longitudinal struts may also have integrated bus bars. These embodiments usually operate on low voltage, in particular in the range from 12 to 24 V, in order that the profile size of the longitudinal struts remains within certain limits, so that an esthetic design of the furniture is still possible. In the case of all these known systems, modular extension, in particular also of the electrification, is possible only to a restricted extent.
If furniture systems are extended, reduced or changed over, the cabling must be laboriously adapted each time to the new situation. If the cabling of a furniture system was laid during constructionxe2x80x94for example in the floor, the walls or the ceilingxe2x80x94, additional complex adaptations are necessary.
All the known systems do not satisfy the requirements which have to be met by a modular furniture system of today and the future.
The object of the invention is to provide electrification of a furniture system which prevents a tangle of cables and makes allowance for user-specific requirements, in particular in the case of modular furniture systems, to the extent that the electrification can be adapted by the user himself with minimal effort.
The way in which the object is achieved is defined by the features of claim 1. According to the invention, the electrification of the furniture system has a multiple plug which can be fastened to a part of the structural element. This multiple plug is fed by a cable of a predetermined length, which is carried by a structural element and serves as an electrical connection between multiple plugs of two neighboring structural elements of the furniture system.
By this system for electrification, a tangle of cables is prevented and the advantages of a modular furniture system are nevertheless retained. The modularity of the furniture system demands that, in spite of the cabling, the structural elements can be changed over, the number of structural elements can be increased or reduced. In particular, this must be possible quickly, easily and while ensuring orderly cable routing. The cable carried by a structural element of the furniture system may be accommodated, for example, in what is known as a cable duct or a recess in the structural element. Some other form of fastening to the structural element is also conceivable. The terminals of the cables are inserted into the multiple plug and consequently form a flexible and user-friendly electrical connection. The fastening of the multiple plug to a part of the structural element allows it to be attached at a height in a flexible rangexe2x80x94within the constraints of the cable length available. Furthermore, the neighboring structural elements of the furniture system can be arranged in series against one another as desired.
To ensure the easy operation of, for example, lighting which is fastened to an upper part of the structural element, a switch or a button may also be fastened to a part of the structural element of the furniture system. Previously, the switch or button was often arranged directly on a light fitting. The upper part of the structural element is usually arranged at a height of 1.80 to 2.20 m, which sometimes makes it difficult to operate the light fitting and, for short people in particular, significantly impairs the ease of operating such a modular furniture system. This switch or button may also serve as a main switch of an entire group of items of electrical equipment (for example computers, printers, desk lamps, etc.). Apart from the use of switches or buttons, sensors may also be used.
One advantage is the displaceable fastening of the multiple plug and/or the switch or button. Specifically in the case of the switch or button, the height can consequently be set to the individual height of the user. In particular, the displaceable fastening possibilities of the multiple plugs allow a modular set-up of the structural elements to be ensured even when they are, for example, arranged at different distances from one another.
A slide-like design of the fastening means is preferred. This makes it possible for the multiple plug, for example, to be displaced as desired. The multiple plug is held in its position by friction. If additional securement is desired, the multiple plug can also be fixedly fastened. Such fixed fastening may take the form of a screwed connection.
To give the user reference points for suitable positioning of the multiple plugs, switches, buttons and sensors, a set incrementation may be predetermined. This comprises a relatively large number of predetermined positions at which, and only at which, these accessories can be fastened.
The modular furniture system comprises at least two longitudinal struts. For structural design reasons, the individual component parts of the electrification (for example multiple plugs, buttons or switches) are preferably fastened to these longitudinal struts. Depending on the basic form of the individual structural element (triangle, square or rectangle, trapezoid, polygon, etc.), the number of longitudinal struts may vary.
The furniture system preferably comprises a plurality of closed structural elements. Such a structural element is formed, for example, by a rectangular frame which comprises at least two lateral longitudinal struts and at least two horizontally arranged stays at the top and bottom. Such structural elements are described for example in WO 98/38705. At least one of the cables is preferably held directly or indirectly on one of these stays. Indirect holding can be realized by a cable carrier (which is designed for example in a dish-shaped form) being arranged on such a stay. In this case, the cable carrier is preferably designed in such a way that it can be clipped onto the corresponding stay by means of a snap mechanism. A dish in the form of a duct is preferably produced from plastic. If the edges of the profile leave a free space, at least on one side, between the stay and the edge of the dish, subsequently occurring cables can be unproblematically accommodated in this profile.
Furthermore, stand constructions which can be added to in order to form office landscapes are known. Such modular systems are described in U.S. Pat. No. 5,522,324 (van Gelder et al.) and in U.S. Pat. No. 5,715,760 (Frascaroli et al.). It is in accordance with the purposes of the invention that the electrification according to the invention can also be provided on such furniture systems.
A further variant of the configuration just described is a structural element which is formed by a closed cuboid. This comprises, for example, four lateral longitudinal struts which between them are provided with struts arranged at the top, bottom and depthwise. Such closed cuboids are known in particular from display cabinet construction.
The longitudinal struts are preferably designed in such a way that the multiple plug and the switch can be fastened at any desired height. The arrangement of the multiple plug is determined by the length of the cables used, of a predetermined length, which form the electrical connection. The fastening is preferably ensured by a clip-in mechanism in a longitudinal slot. Apart from the preferred design in the form of longitudinal slots, the fastening means on the frame may also be transverse slots, protruding studs or entire ridges. The multiple plugs are fastened to the protruding fastening means in a way analogous to the fastening in the longitudinal slots.
The clip-in mechanism is preferably designed in such a way that, after the fastening of the multiple plug to the fastening means of the frame, said plug continues to be displaceable. One variant of this is the predetermination of specific positions for the fastening means (for example set increments), at which the multiple plug is fastened. Displacement of the multiple plug is possible only at the specific positions.
It is obvious that other known systems which make it possible for a housing to be clipped into a recess can also be used. The longitudinal slots may be provided on all four sides of the longitudinal struts. However, two longitudinal slots are preferably arranged, lying opposite each other and located on the sides of the longitudinal struts which remain free after the fitting of working or usable surfaces of the furniture system or the arrangement of the structural elements in series. The longitudinal slots are preferably provided on the sides which are aligned parallel to the plane formed by the rectangular frame. These longitudinal slots may also serve for accommodating cables which lead from the multiple plug to the loads. Possibly occurring excess lengths of the cables can be accommodated in the longitudinal slots of the longitudinal struts. If, instead of longitudinal slots, studs are arranged as fastening means on the frame, cable ducts in which excess lengths of cables can be accommodated can also be clipped in.
The structural elements are preferably electrified from one side, from the right or left side in relation to a frontal view. For example, the multiple plug is fastened to the longitudinal strut which is further away from the connection to the power supply than the other longitudinal strut of the same structural element. If electrification takes place from the left side, in relation to a frontal view, the multiple plug is fastened to the right longitudinal strut. In the case of the neighboring structural element and every further structural element, the multiple plug is accordingly also attached to the right longitudinal strut. In the case of electrification from the right side, in relation to a frontal view, the arrangement is correspondingly mirror-inverted. This results in fastening of the multiple plug to the left longitudinal strut. The aim is to create comprehensive electrification (i.e. satisfying all the needs of the user in an individual case) with minimum possible use of cables of a standardized length. Uniformity within the overall interior installation is aimed for. It is in accordance with the purposes of the invention that the functionality of the furniture system and the needs of the users are at the forefront with respect to the arrangement of the multiple plugs.
Depending on local conditions and the individual wishes of the users, it is also conceivable to arrange the structural elements in a star-shaped manner. In this case, electrification from the ceiling or else from the floor at the center of the star-shaped arrangement would be preferred, but not mandatory. Furthermore, two structural elements can also have multiple plugs arranged mirror-invertedly. This is for the purpose that the multiple plug may be fastened to the left longitudinal strut, in relation to a frontal view, in the case of one structural element, and the next multiple plug, on the neighboring structural element, may be fastened to the right longitudinal strut, here, too, in relation to a frontal view.
Depending on the arrangement, it is also conceivable for one of the longitudinal struts to form the cable-carrying element of the structural element. In this case, the upper and lower horizontal stays would be provided with corresponding fastening means, in which the multiple plugs and/or switches or buttons would be clipped. For esthetic reasons, and to prevent the cables accommodated in the slots from coming out, covers, which can preferably be clipped in, are attached on this longitudinal slot. The mechanism which makes it possible for the cover to be clipped in may be designed in a way corresponding to the clip-in mechanism of the multiple plugs. These covers are adapted in situ to the existing arrangement, since they are interrupted by multiple plugs, switches and leads running off to electrical equipment.
In order that a tangle of cables is not created, the cable length is preferably to be limited. For esthetic and design reasons, the upper or lower horizontal stay is preferred as the carrying element of the overall structural element. As a result, the length of the cable which establishes the electrical connection between the structural elements of the furniture system is preferably the length of the horizontally connecting stay plus an excess length, which is approximately one fifth of the length of the longitudinal strut. The excess length may also correspond to the length of a longitudinal strut. Depending on the application and individual user wishes, intermediate sizes or user-specific lengths of the cables may also be used.
In the case of a symmetrical or identical arrangement of the multiple plugs on the longitudinal struts, the cables of the predetermined length consequently result in a placement of the multiple plugs in the lower region of the longitudinal strut, at approximately a height between one tenth and half the overall height of the corresponding longitudinal strut.
Office set-ups of today must offer flexibility and individuality and have developed increasingly into actual office landscapes (for example, integral interior furnishing systems). For this reason, certain elements, such as the lighting of such office landscapes for example, are centrally controlled. This cabling is separate from the actual electrification. However, in order here, too, to prevent a tangle of cables, these control elements are combined with the electrification of the furniture system. The additional holders for the control elements are, for example, detachably fastened to the longitudinal struts or directly to the multiple plugs. The fastening preferably takes the form of a clip-in mechanism. The construction of these holders is comparable to those [sic] of the multiple plugs of the electrical supply. Since the control elements are preferably operated in the low voltage range, the dimensions of these holders are reduced in comparison with those of the multiple plugs. It is preferred for the additional holders to be able to be fastened to the multiple plugs in different positions. The fastening means on the multiple plugs may also be designed in such a way that further multiple plugs can be fastened to them.
The cabling of the controller is preferably based on a standard, such as EIB, DALI or LON for example. A generally known standard which makes it possible to allow all stations to communicate bidirectionally with one another via a decentralized system is preferably used for the controller. In addition, energy and lengths of line can be saved by the use of such systems.
When such a standard is used, the button or switch may be replaced by a sensor. Like the button or the switch, the sensor is preferably displaceably fastened to one of the longitudinal struts, which, however, does not rule out the variant of integration on or in a multipoint connector. When actuated by a user, the sensor passes on to the central system the desired intervention in the central control of the lighting. In order that a general lighting concept can be retained in spite of the possibilities for manual intervention, it is conceivable to specify in the PC-supported control tolerance ranges which must not be exceeded. By such a restriction, it is possible to minimize disturbances at other workplaces caused by manual intervention at one of the workplaces.
A preferred design of a multiple plug for a modular furniture system comprises a housing and an exchangeable, clipped-in multiple coupling insert. Exchangability of the multiple coupling insert makes flexible use of the multiple plug possible. Depending on the alignment, the multiple plug can be adapted to the local conditions. In addition, exchangability also has advantageous effects on long-term use, in particular with respect to the housing. Should the multiple coupling insert be defective one day or if some other plug system is used in the future, the existing cabling can simply continue to be used, since only the multiple coupling insert has to be exchanged.
In order that a displaceable fastening of the multiple plug is possible, the housing has a clip-in mechanism at least on one outer side. This clip-in mechanism is made to clip or engage in the longitudinal slot, for example by two inwardly displaceable xe2x80x9ctonguesxe2x80x9d of plastic, with pressure being applied to the outer side of the multiple plug lying opposite the clip-in mechanism. By pressing the xe2x80x9ctonguesxe2x80x9d of plastic together, the multiple plug can be removed without destroying it and attached at another location. In theory, it would be conceivable to provide a clip-in mechanism for fastening the multiple plug to one of the longitudinal struts on more than one outer side of the housing. In the preferred design of the multiple plug, however, the three remaining outer sides are provided with fastening means for the holders of the control elements.
The fastening of the multiple coupling insert within the housing is designed in such a way that, on the one hand, the tensile forces occurring, which arise in particular when the cables are removed, can be absorbed and, on the other hand, later removal of the multiple coupling insert is possible. The multiple coupling insert is designed accordingly. Clip-in mechanisms made to match one another, which are already known on the market, are preferably used.
In a preferred embodiment, the outer sides of the housing of the multiple plug which have no clip-in mechanism for fastening the multiple plug, for example to a longitudinal strut, have recesses which serve as fastening means for the holders of the control elements. Since preferably only one outer side of the housing is provided with a clip-in mechanism, three different fastening possibilities for the holders of the control elements are obtained. In a modification of the configuration described, one or more outer sides of the housing of the multiple plug may also be designed in such a way that a further multiple plug can be fastened to them, in the manner of the multiple plugs for the electrification.
A multiple coupling insert which can be clipped into the housing preferably has at least one incoming feed and at least two taps. In this case, at least one of these taps is reserved for the further electrical connection of the neighboring structural element. In a preferred embodiment, which ensures optimum compactness of the multiple plug, two taps are arranged in one direction and one tap and the incoming feed are arranged in the opposite direction. The tap which is aligned in the same direction as the incoming feed is preferably the tap which serves for the further electrical supply to the neighboring structural element. The two other taps are preferably arranged in the direction of the electrical loads or the lighting.
To make global use of the modular furniture system with the electrification possible, and to keep the size of the multiple plug as small as possible, the terminals are preferably special plug systems. A plug system preferred for the electrification of the modular furniture system must, on the one hand, meet the various national requirements and, on the other hand, at the same time be approved in various countries. Various such plug systems are already available on the market (for example xe2x80x9cgesisxe2x80x9d, Wieland Electric GmbH, Bamberg Germany). The dimensions of the multiple plug are dependent on the dimensions of the plugs of the selected plug system. The more compact the plug is made, the more compact the multiple plug also becomes.
An example of a compact plug has a rectangular form, in which the width is approximately one third of the length of the plug. In the case of such a plug, preferably three contact elements are arranged one behind the other, the middle contact element preferably being the grounding. The relatively flat design of such a plug allows two plugs to be arranged at a small distance from each other. This results in the preferred, approximately square basic form of the housing of the multiple plug of the electrical supply. The housing consequently has a cylindrical (prism) tubular form, dispensing with terminations underneath and on top, in order that the plugs can be plugged in and unplugged. The corners of the housing are preferably highly beveled. This provides an esthetic design of the housing and can at the same time serve for coding the plugs.
The height of the multiple plug is determined on the one hand by the design of the coupling and on the other hand by a guide part, which assists coding and meets safety and esthetic requirements for the accommodation of such a plug. Since the multiple plug for the control elements is clipped in on the multiple plug of the electrical supply, it is preferably of the same length and height as this multiple plug. The width is determined by the use of the corresponding plugs of the control elements. Here, too, various control element components are already available on the market. In the application of the control system, plugs which have to withstand a lower test voltage than is the case with plugs for electrification are used. This allows the holders of the control elements to be made smaller than the corresponding multiple plugs. This has a decisive influence in particular on the width of the holder of the EIB system. Such a holder, which may also be called a multiple plug of the control elements, has as a result only a width which is slightly greater than half the length of a multiple plug.
Further advantageous embodiments and combinations of features of the invention emerge from the following detailed description and the complete set of patent claims.